We sailed round trip on the July 5 - 12, 2009 voyage of the Royal Caribbean Lines (RCL) Mariner of the Seas from San Pedro/Los Angeles to the Mexican Riviera with stops at Cabo San Lucas, Mazatlan and Puerto Vallarta. Our inside, windowless cabin was  on the ninth deck, midships. We booked  a great senior citizen rate on an inside cabin rather than pay more for an ocean view window or balcony and were quite happy with our decision as the cabin was very quiet and adequate for our needs.  Note - a passenger vetoed  the "Promenade view" cabins as they have windows that look out on to the main promenade, which features music,  dancing and lots of people sometimes into the late hours. We were told by this experienced cruiser who inadvertently booked one of these rooms that sounds from the Promenade can be heard inside the cabin. Booking suggestion - shop the Internet for the best price, including any give backs such as on-board credits or pre-pay of tips. Different booking sites generally offer the same price for a given cabin BUT offer different incentive give backs. Also,  check for a military/senior citizen discount. We booked our own air fare (RCL might not be the best deal on either the cabin price or a fly/sail package).  In summary, we found Mariner of the Seas to be a fantastic ship, with delicious food, friendly, helpful and attentive crew. Our likes and dislikes are mentioned below. What We Liked ·         The ship is huge, has many activity areas and is spotlessly clean ·         The crew, especially the dining staff and cabin attendent, are friendly,  attentive and very efficient at their jobs ·         Most areas of the ship are non-smoking (THANKFULLY all cabins are non-smoking!) ·         The Captain is friendly, gregarious and very interactive with the passengers ·         Embarkation and debarkation were extremely well organized, went smoothly and quickly considering there were 3,500 passengers ·         There were lots of activities to keep people busy if you wanted to be busy, or you could relax by the pool or in the library. There was entertainment every night. Not to be missed - the Married Couples Game, Quest and the ice skating show. ·         The main dining room on three levels (decks) was elegant, with really delicious food. We didn't hesitate to request additional portions of anything (appetizer, entrEe or dessert). We liked the early (6 PM) seating. We sat at a table for eight and enjoyed wonderful company who enhanced our dining experience. Suggestion - if people at your dining table are strangers to each other, get into action. Introduce yourselves, and inquire about their hometowns, how many cruises they have been on, etc.  - this usually is a silence-breaker at mealtimes. ·         If you chose not to go to the dining room for meals, the Windjammer buffet restaurant offers a good selection of food in an informal atmosphere ·         A real treat! - Cafe Promenade was open all hours with light sandwiches, desserts and beverages, free of charge. All kindsof pizza too. ·         The midnight buffet, poolside one evening, was enjoyable with an awesome selection of food with lots of intricately decorated food carvings and ice sculptures ·         Access to free ice cream machines by the pool until 9 PM every night ·         The RCL bus shuttle from LAX to San Pedro was $55 per person round trip. It was very well organized and a good value What Could Have Been Better (mostly nitpicks) ·         At certain times of the day (e.g., meal times and port calls) there could be long waits for an elevator ·         Alcohol cannot be brought on the ship, and you pay $6.75 to $8.75 for wine or drinks, including in the main dining room ·         Soft drinks are an extra cost. Buy a whole cruise (unlimited ) soft drink pass for around $25 for each of your kids ·         There is some commercialization, with jewelry sales, art sales, photograph sales (in one area only) ·         The very hot summer is not the best time to visit Mexico, although the heat is not an issue at sea. In Cabo San Lucas it was unmerciful during a walking tour. Summer time solution - we took escorted air conditioned, comfortable bus tours in the other port cities. This was a good solution to the heat issue. Some comments about shore excursions - since this was a first-time cruise experience, we booked tours through the ship's tour director. We relied on the ship-approved tour to get us back on time so that the ship wouldn't sail without us. It is true that some people are late from shore excursions and the ship departs without them. There were reports that some people were late and left behind on the prior week's cruise. The tours booked onboard are more expensive than tours you can book yourself on the Internet or on the dock (some more experienced passengers booked their own tours). Cabo San Lucas - offers many water sports activities and there are "day at a resort" packages. The walking tour of downtown Cabo was not pleasant (merciless heat, downtown is not particularly interesting or attractive). There are some newly developed resort complexes and there is much development in progress. Mazatlan - Same thing as Cabo - many water sports activities. This time we took an air-conditioned bus tour of the city, which included a Mexican folk show (very worthwhile, entertaining and good quality).  The downtown fails to excite. Our guide was cheerful, knowledgeable and fun. Puerto Vallarta - this is a much bigger city than either of the other port stops. We took an air conditioned bus tour of the city, which included a tequila factory tour that also offered a nice outdoor lunch and folk show. We enjoyed the outing. The old town part of Puerto Vallarta is somewhat charming and would be worth a day of wandering around the plentiful shops . Again our guide did a very good job on the 4.5  hour tour.